Which one of the following planets has no natural satellites?
Show Hint
Only the first two planets from the Sun, Mercury and Venus, have no natural satellites.
All other planets in the Solar System have at least one moon (Earth has 1, Mars has 2, and the outer gas giants have dozens).
Step 1: Understand the question. We need to identify which planet among the options has absolutely no natural satellites or moons orbiting it. Step 2: Recall the satellites of each planet. Jupiter has over 95 known moons. Mars has 2 moons: Phobos and Deimos. Saturn has over 140 known moons. Mercury, like Venus, has zero natural satellites. Step 3: Confirm the answer. Mercury is the smallest planet in our solar system and has no natural satellites orbiting it, making it the correct answer. \[ \boxed{\text{Mercury}} \]